Manipulation of concentrated suspensions is challenging in microfluidics due to the complex physics involved. We studied the behaviour of a dense suspension (blood sample of volume fraction > 0.1) coflowing with an aqueous buffer in a microchannel exposed to standing bulk acoustic waves using experiments and theoretical modeling. The coupled effect of acoustophoretic particle migration and bulk relocation due to an inhomogeneous fluid configuration led to interesting phenomena. The study revealed that depending on the acoustic impedance of the suspension and the buffer streams, different flow regimes: complete relocation, acoustic migration, non-relocation/migration and partial relocation can be observed. The occurrence of different regimes is explained by the contrast in acoustic impedance between the streams and the particle and the relevant timescales. We discovered the partial relocation regime; wherein acoustic migration of particles forms a band of highly concentrated suspension at the suspension-buffer interface that relocates to the pressure node. The partial relocation regime thus offers a new technique for the acoustic-driven splitting of a suspension stream into denser and diluted suspension streams.